Miata Mailing List: March 1996, Message #84
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   From: LSAPEX@aol.com
Subject: Re: Tie Downs/Towing
   Date: Sat, 2 Mar 1996 10:08:23 -0500

>The tie-down loop is constructed from 0.4 in dia steel stock.  In tension,
>straight out from the car, they will support on the order of 25,000 lb.
>Each.
>If the four retaining bolts shear, the failure load would be about 30,000
lb.
>This is neglecting the friction between the tie-down and the frame of the
car
>generated by the tension in the tightened bolts.  The friction alone will
>hold
>5,000 lb.  On the other hand, if the tie-down is to fail by bending, it will
>require almost 10,000 lb straight down.  Straight toward the ground is the
>weakest orientation for this part.  Unfortunately there may come a time when
>flat towing a broken Miata or securing it to a trailer is appropriate.
 These
>activities are not outside the strength capabilities of the hardware
>supplied.

What is the strength of the frame rail were the tow hook bolts to?
I've seen, and heard of a few Miatas having damage to the frame rail in
shipping. It does bend.
I think this is the concern that Mazda has.

Lester Seal
Mass Miata
Team APEX